Pub Date : 1900-01-01DOI: 10.1109/ACSSC.2005.1600003
N. Sandgren, P. Stoica
The computational complexity of a parametric spectral analysis method usually increases rapidly for large numbers of measured signal samples. Splitting the considered frequency range into several s ...
对于大量的测量信号样本，参数谱分析方法的计算复杂度通常会迅速增加。将考虑的频率范围分成几个s…
{"title":"Sub-Band Cramer-Rao Bounds for Frequency-Selective Spectral Analysis","authors":"N. Sandgren, P. Stoica","doi":"10.1109/ACSSC.2005.1600003","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1600003","url":null,"abstract":"The computational complexity of a parametric spectral analysis method usually increases rapidly for large numbers of measured signal samples. Splitting the considered frequency range into several s ...","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"155 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128699737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/ACSSC.2005.1599829
B. Liu, Hui Liu, S. Roy
The Tomlinson-Harashima precoding is well known for dirty paper coding implementation. Despite its simplicity, THP suffers from a significant performance loss in the low SNR region due to modulo operations. In this paper, we propose new dirty paper precoding scheme by taking advantage of the known modulation structure of interference (e.g., BPSK and QPSK signals). The new method, termed structured DPC (SDPC), outperforms the regular THP with modest changes to the transmitter and receiver. For BPSK and QPSK cases investigated, the SDPC only suffers power loss, which is up to 1.25 dB compared with non-interference case, while the regular THP-based scalar dirty paper coding has a typical 4-5 dB capacity loss in the same low SNR regions
{"title":"Structured Dirty Paper Coding with Known Interference Structure at Receiver","authors":"B. Liu, Hui Liu, S. Roy","doi":"10.1109/ACSSC.2005.1599829","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599829","url":null,"abstract":"The Tomlinson-Harashima precoding is well known for dirty paper coding implementation. Despite its simplicity, THP suffers from a significant performance loss in the low SNR region due to modulo operations. In this paper, we propose new dirty paper precoding scheme by taking advantage of the known modulation structure of interference (e.g., BPSK and QPSK signals). The new method, termed structured DPC (SDPC), outperforms the regular THP with modest changes to the transmitter and receiver. For BPSK and QPSK cases investigated, the SDPC only suffers power loss, which is up to 1.25 dB compared with non-interference case, while the regular THP-based scalar dirty paper coding has a typical 4-5 dB capacity loss in the same low SNR regions","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129022981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/ACSSC.2005.1599852
Jing Hu, J. Gibson
We generate nonuniform quantization parameter (QP) matrices to improve the perceptual quality of reconstructed video in the AVC/H.264 standard. The resulting 9 QP matrices are indexed to the 9 intra-frame prediction modes of the 4 times 4 blocks and can be applied to the 16 times 16 macroblock (MB)s which engage only the first 4 out of the 9 intra-modes. We also studied how the nonuniform QP matrices are affected by the local luminance level and the video frame rate. Two subjective experiments exploiting the luminance, texture, and temporal masking properties of the human vision system are conducted to generate the results. A third subjective experiment is conducted to evaluate the derived scheme. The data we collect from this experiment show that using the QP matrices instead of a uniform QP considerably improves the perceptual quality of AVC/H.264 compressed video sequences. Some implementation details are discussed
{"title":"Intra-Mode Indexed Nonuniform Quantization Parameter Matrices in AVC/H.264","authors":"Jing Hu, J. Gibson","doi":"10.1109/ACSSC.2005.1599852","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599852","url":null,"abstract":"We generate nonuniform quantization parameter (QP) matrices to improve the perceptual quality of reconstructed video in the AVC/H.264 standard. The resulting 9 QP matrices are indexed to the 9 intra-frame prediction modes of the 4 times 4 blocks and can be applied to the 16 times 16 macroblock (MB)s which engage only the first 4 out of the 9 intra-modes. We also studied how the nonuniform QP matrices are affected by the local luminance level and the video frame rate. Two subjective experiments exploiting the luminance, texture, and temporal masking properties of the human vision system are conducted to generate the results. A third subjective experiment is conducted to evaluate the derived scheme. The data we collect from this experiment show that using the QP matrices instead of a uniform QP considerably improves the perceptual quality of AVC/H.264 compressed video sequences. Some implementation details are discussed","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129680281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/ACSSC.2005.1599957
K. Ozonat
We consider the problem of classification based on Gauss mixture models for a simple network of two sensors with noisy observations. The goal of each sensor is to give a classification decision based on its noisy observation and the help it receives from the other sensor under the given rate constraint. We formulate the problem as a vector quantization problem and design a Lloyd optimal quantizer, minimizing the classification error for the given rate constraint. Our cross-validated simulations, using a set of aerial images, indicate an improvement in the classification performance (for the given rate constraints) when compared with simple extensions of previously published GMM-based algorithms.
{"title":"Gauss Mixture Model Clustering for Noisy Images under Rate Constraints","authors":"K. Ozonat","doi":"10.1109/ACSSC.2005.1599957","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599957","url":null,"abstract":"We consider the problem of classification based on Gauss mixture models for a simple network of two sensors with noisy observations. The goal of each sensor is to give a classification decision based on its noisy observation and the help it receives from the other sensor under the given rate constraint. We formulate the problem as a vector quantization problem and design a Lloyd optimal quantizer, minimizing the classification error for the given rate constraint. Our cross-validated simulations, using a set of aerial images, indicate an improvement in the classification performance (for the given rate constraints) when compared with simple extensions of previously published GMM-based algorithms.","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126809157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/ACSSC.2005.1599997
J. M. Romero-Jerez, J. P. Peña-Martín, A. Porras-Galvez, M. Ruiz-García
Two tight closed-form approximated expressions for the outage probability of equal-gain combining (EGC) are presented for the case of co-channel interferers with arbitrary powers in Rayleigh fading. A recent exact expression for the outage probability is extended to account for arbitrary power interferers for the sake of comparison. Comparisons between this new approach and the exact solution for EGC show excellent agreement. Contrary to most previous works in the subject, our analysis is suitable for performance evaluation of power controlled multi-cell networks, in which in-cell users are received with equal average powers and other cell-users are received with different average powers. In addition, we provide a comparison of outage probability for EGC, maximal ratio combining (MRC) and selection combining (SC) for arbitrary power interferers.
{"title":"Outage Probability of EGC Under Co-Channel Interferers with Arbitrary Powers in Rayleigh Fading","authors":"J. M. Romero-Jerez, J. P. Peña-Martín, A. Porras-Galvez, M. Ruiz-García","doi":"10.1109/ACSSC.2005.1599997","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599997","url":null,"abstract":"Two tight closed-form approximated expressions for the outage probability of equal-gain combining (EGC) are presented for the case of co-channel interferers with arbitrary powers in Rayleigh fading. A recent exact expression for the outage probability is extended to account for arbitrary power interferers for the sake of comparison. Comparisons between this new approach and the exact solution for EGC show excellent agreement. Contrary to most previous works in the subject, our analysis is suitable for performance evaluation of power controlled multi-cell networks, in which in-cell users are received with equal average powers and other cell-users are received with different average powers. In addition, we provide a comparison of outage probability for EGC, maximal ratio combining (MRC) and selection combining (SC) for arbitrary power interferers.","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130631195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/ACSSC.2005.1600000
M. Schubert, Shuying Shi, Eduard Axel Jorswieck, H. Boche
We address the problem of Mean Square Error (MSE) transceiver design for point-to-multipoint transmission in multi-user Multiple-Input-Multiple-Output (MIMO) systems. We solve the problem of minimizing the downlink sum MSE under a sum power constraint by jointly optimizing the linear transmitters and receivers. Our result is based on a "duality" between downlink and uplink MSE regions. It states that downlink and uplink share the same achievable MSE region under a sum power constraint. Thus, the problem of downlink design can be solved efficiently by focusing on an equivalent uplink problem.
{"title":"Downlink Sum-MSE Transceiver Optimization for Linear Multi-User MIMO Systems","authors":"M. Schubert, Shuying Shi, Eduard Axel Jorswieck, H. Boche","doi":"10.1109/ACSSC.2005.1600000","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1600000","url":null,"abstract":"We address the problem of Mean Square Error (MSE) transceiver design for point-to-multipoint transmission in multi-user Multiple-Input-Multiple-Output (MIMO) systems. We solve the problem of minimizing the downlink sum MSE under a sum power constraint by jointly optimizing the linear transmitters and receivers. Our result is based on a \"duality\" between downlink and uplink MSE regions. It states that downlink and uplink share the same achievable MSE region under a sum power constraint. Thus, the problem of downlink design can be solved efficiently by focusing on an equivalent uplink problem.","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123880149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/ACSSC.2005.1599845
W. Gross, V. Gaudet, A. Milner
LDPC codes are found in many recent communications standards such as 10GBASE-T, DVB-S2 and IEEE 802.16 (WiMAX). We present a review of a new class of "stochastic" iterative decoding architectures. Stochastic decoders represent probabilistic messages by the frequency of ones in a binary stream. This results in a simple mapping of the factor graph of the code into silicon. An FPGA implementation of a LDPC decoder with 8 information bits and 8 coded bits is described. On an Altera Cyclone FPGA, the throughput is 5 Mbps when clocked at 100 MHz and is expected to increase nearly linearly with the code length. Simulations of the decoder on an Altera Stratix FPGA indicate a potential throughput of 8 Mbps
{"title":"Stochastic Implementation of LDPC Decoders","authors":"W. Gross, V. Gaudet, A. Milner","doi":"10.1109/ACSSC.2005.1599845","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599845","url":null,"abstract":"LDPC codes are found in many recent communications standards such as 10GBASE-T, DVB-S2 and IEEE 802.16 (WiMAX). We present a review of a new class of \"stochastic\" iterative decoding architectures. Stochastic decoders represent probabilistic messages by the frequency of ones in a binary stream. This results in a simple mapping of the factor graph of the code into silicon. An FPGA implementation of a LDPC decoder with 8 information bits and 8 coded bits is described. On an Altera Cyclone FPGA, the throughput is 5 Mbps when clocked at 100 MHz and is expected to increase nearly linearly with the code length. Simulations of the decoder on an Altera Stratix FPGA indicate a potential throughput of 8 Mbps","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"28 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121000934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/ACSSC.2005.1599753
Gong Dong, S. Acton
In this paper, we propose an algorithm for the identification of objects from a noisy and cluttered background in video sequences. Our algorithm is based on the marked point process (MPP) framework, which provides a useful tool for integrating object spatial information into the identification process. The maximum a posteriori (MAP) estimation of a set of points corresponding to the centroids of objects observed in the image is obtained via a Markov chain Monte Carlo algorithm. The optimal solution, in terms of the MAP principle, is computed with respect to all objects in the scene, rather than single objects. The algorithm is applied to real data: intravital microscopic rolling leukocyte video datasets. A quantitative study of our approach demonstrates that the proposed approach can serve as a fully automated substitute to the tedious manual rolling leukocyte detection process
{"title":"Object Identification by Marked Point Process","authors":"Gong Dong, S. Acton","doi":"10.1109/ACSSC.2005.1599753","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599753","url":null,"abstract":"In this paper, we propose an algorithm for the identification of objects from a noisy and cluttered background in video sequences. Our algorithm is based on the marked point process (MPP) framework, which provides a useful tool for integrating object spatial information into the identification process. The maximum a posteriori (MAP) estimation of a set of points corresponding to the centroids of objects observed in the image is obtained via a Markov chain Monte Carlo algorithm. The optimal solution, in terms of the MAP principle, is computed with respect to all objects in the scene, rather than single objects. The algorithm is applied to real data: intravital microscopic rolling leukocyte video datasets. A quantitative study of our approach demonstrates that the proposed approach can serve as a fully automated substitute to the tedious manual rolling leukocyte detection process","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121420304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/ACSSC.2005.1599798
X. Wang, Yingqun Yu, A. Ribeiro
A novel cooperative spread spectrum random access (CSSRA) protocol has been recently proposed. It is shown that thanks to user cooperation the novel protocol can capture part of the available diversity and achieve a marked increase in maximum stable throughput over its non-cooperative counterpart. In this paper, we study the finite-user behavior of a one-packet-buffering CSSRA system with Poisson packet arrivals and derive pertinent performance metrics including throughput, packet loss rate and average packet delay. With the proposed analysis framework, we compare the performance of CSSRA with that of non-cooperative SSRA for a Rayleigh fading channel to illustrate the advantage of user cooperation in terms of throughput as well as delay
{"title":"Performance Analysis of Cooperative Random Access with Long PN Spreading Codes","authors":"X. Wang, Yingqun Yu, A. Ribeiro","doi":"10.1109/ACSSC.2005.1599798","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599798","url":null,"abstract":"A novel cooperative spread spectrum random access (CSSRA) protocol has been recently proposed. It is shown that thanks to user cooperation the novel protocol can capture part of the available diversity and achieve a marked increase in maximum stable throughput over its non-cooperative counterpart. In this paper, we study the finite-user behavior of a one-packet-buffering CSSRA system with Poisson packet arrivals and derive pertinent performance metrics including throughput, packet loss rate and average packet delay. With the proposed analysis framework, we compare the performance of CSSRA with that of non-cooperative SSRA for a Rayleigh fading channel to illustrate the advantage of user cooperation in terms of throughput as well as delay","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114849685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/ACSSC.2005.1600021
P. Ding, D. Love, M. Zoltowski
For multiple antenna broadcast channels, perfect channel state information (CSI) at the basestation plays a critical role in achieving the sum rate advantage provided by the multiple antennas. For practical system implementation, the CSI is usually estimated from training sequences. In this paper, we study the effect of channel estimation error on the sum rate capacity of multiple antenna broadcast channels. A lower bound is derived based on the sum rate performance of the zero forcing dirty paper coding scheme under CSI estimation error. A cooperative upper bound is established from the capacity upper bound of a single user multiple-input multiple-output (MIMO) channel given the same channel imperfectness. We further analyze the asymptotic sum rate loss caused by channel estimation error. If we assume that the variance of the channel estimation error is fixed, imperfect CSI results in a sum rate ceiling for high SNR. For systems with orthogonal training sequences and minimum mean square error (MMSE) channel estimator, the asymptotic sum rate loss is about N bit per channel use where N is the number of transmit antennas. I. INTRODUCTION Techniques employing multiple antennas are important for wireless communication systems because they provide the possibility of a significant increase in system spectrum effi- ciency. In the last decade, lots of works have been done on point-to-point, i.e., single user, multiple-input multiple-output (MIMO) systems. Larger rate gains, however, are available when MIMO multi-user systems are considered. Recently, the sum rate capacity of the multiple antenna broadcast channel, which models the downlink in a MIMO cellular network, was solved (1), (2), (3), (4). These works show that perfect channel state information (CSI) at the basestation is critical for the system to achieve the sum rate advantage. With perfect CSI,
{"title":"On the Sum Rate of Multi-Antenna Broadcast Channels with Channel Estimation Error","authors":"P. Ding, D. Love, M. Zoltowski","doi":"10.1109/ACSSC.2005.1600021","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1600021","url":null,"abstract":"For multiple antenna broadcast channels, perfect channel state information (CSI) at the basestation plays a critical role in achieving the sum rate advantage provided by the multiple antennas. For practical system implementation, the CSI is usually estimated from training sequences. In this paper, we study the effect of channel estimation error on the sum rate capacity of multiple antenna broadcast channels. A lower bound is derived based on the sum rate performance of the zero forcing dirty paper coding scheme under CSI estimation error. A cooperative upper bound is established from the capacity upper bound of a single user multiple-input multiple-output (MIMO) channel given the same channel imperfectness. We further analyze the asymptotic sum rate loss caused by channel estimation error. If we assume that the variance of the channel estimation error is fixed, imperfect CSI results in a sum rate ceiling for high SNR. For systems with orthogonal training sequences and minimum mean square error (MMSE) channel estimator, the asymptotic sum rate loss is about N bit per channel use where N is the number of transmit antennas. I. INTRODUCTION Techniques employing multiple antennas are important for wireless communication systems because they provide the possibility of a significant increase in system spectrum effi- ciency. In the last decade, lots of works have been done on point-to-point, i.e., single user, multiple-input multiple-output (MIMO) systems. Larger rate gains, however, are available when MIMO multi-user systems are considered. Recently, the sum rate capacity of the multiple antenna broadcast channel, which models the downlink in a MIMO cellular network, was solved (1), (2), (3), (4). These works show that perfect channel state information (CSI) at the basestation is critical for the system to achieve the sum rate advantage. With perfect CSI,","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"34 30","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113934310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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